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authorVadim Yanitskiy <axilirator@gmail.com>2017-04-30 19:41:56 +0700
committerVadim Yanitskiy <axilirator@gmail.com>2017-05-07 23:11:06 +0700
commit2c3066e5da54659f19799005eddb1d134c6d0166 (patch)
tree15f243c669d85acfec9308c658ae7c2491cdcf31 /m4
parente604ee39cff121fdb2c6946a230bc2374929b35b (diff)
configure.ac: add SIMD detection capabilities
This change adds a check whether compiler supports some SIMD (Single Instruction, Multiple Data) instructions. It is enabled by default, and can be disabled by configure option --disable-simd. The check macro is based on the AX_EXT from autoconf-archive: www.gnu.org/software/autoconf-archive/ax_ext.html And depends on the ax_check_compile_flag macro: www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html Currently only the following SIMD extensions are being checked: AVX2, SSE3, SSE4.1, but adding others is also possible. All found extensions are being defined in the 'config.h' header. Change-Id: Idf8fff984bd936a75c7c307338df88ba4b005817
Diffstat (limited to 'm4')
-rw-r--r--m4/ax_check_compile_flag.m474
-rw-r--r--m4/ax_check_simd.m482
2 files changed, 156 insertions, 0 deletions
diff --git a/m4/ax_check_compile_flag.m4 b/m4/ax_check_compile_flag.m4
new file mode 100644
index 00000000..dcabb92a
--- /dev/null
+++ b/m4/ax_check_compile_flag.m4
@@ -0,0 +1,74 @@
+# ===========================================================================
+# https://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
+#
+# DESCRIPTION
+#
+# Check whether the given FLAG works with the current language's compiler
+# or gives an error. (Warnings, however, are ignored)
+#
+# ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
+# success/failure.
+#
+# If EXTRA-FLAGS is defined, it is added to the current language's default
+# flags (e.g. CFLAGS) when the check is done. The check is thus made with
+# the flags: "CFLAGS EXTRA-FLAGS FLAG". This can for example be used to
+# force the compiler to issue an error when a bad flag is given.
+#
+# INPUT gives an alternative input source to AC_COMPILE_IFELSE.
+#
+# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
+# macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
+#
+# LICENSE
+#
+# Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or (at your
+# option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+# Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program. If not, see <https://www.gnu.org/licenses/>.
+#
+# As a special exception, the respective Autoconf Macro's copyright owner
+# gives unlimited permission to copy, distribute and modify the configure
+# scripts that are the output of Autoconf when processing the Macro. You
+# need not follow the terms of the GNU General Public License when using
+# or distributing such scripts, even though portions of the text of the
+# Macro appear in them. The GNU General Public License (GPL) does govern
+# all other use of the material that constitutes the Autoconf Macro.
+#
+# This special exception to the GPL applies to versions of the Autoconf
+# Macro released by the Autoconf Archive. When you make and distribute a
+# modified version of the Autoconf Macro, you may extend this special
+# exception to the GPL to apply to your modified version as well.
+
+#serial 5
+
+AC_DEFUN([AX_CHECK_COMPILE_FLAG],
+[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
+AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
+AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [
+ ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS
+ _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"
+ AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
+ [AS_VAR_SET(CACHEVAR,[yes])],
+ [AS_VAR_SET(CACHEVAR,[no])])
+ _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
+AS_VAR_IF(CACHEVAR,yes,
+ [m4_default([$2], :)],
+ [m4_default([$3], :)])
+AS_VAR_POPDEF([CACHEVAR])dnl
+])dnl AX_CHECK_COMPILE_FLAGS
diff --git a/m4/ax_check_simd.m4 b/m4/ax_check_simd.m4
new file mode 100644
index 00000000..d07d706f
--- /dev/null
+++ b/m4/ax_check_simd.m4
@@ -0,0 +1,82 @@
+# ===========================================================================
+# http://www.gnu.org/software/autoconf-archive/ax_ext.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_EXT
+#
+# DESCRIPTION
+#
+# Find supported SIMD extensions by requesting cpuid. When an SIMD
+# extension is found, the -m"simdextensionname" is added to SIMD_FLAGS if
+# compiler supports it. For example, if "sse2" is available, then "-msse2"
+# is added to SIMD_FLAGS.
+#
+# This macro calls:
+#
+# AC_SUBST(SIMD_FLAGS)
+#
+# And defines:
+#
+# HAVE_AVX3 / HAVE_SSE3 / HAVE_SSE4.1
+#
+# LICENSE
+#
+# Copyright (c) 2007 Christophe Tournayre <turn3r@users.sourceforge.net>
+# Copyright (c) 2013 Michael Petch <mpetch@capp-sysware.com>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+#
+# NOTE: The functionality that requests the cpuid has been stripped because
+# this project detects the CPU capabilities during runtime. However, we
+# still need to check if the compiler supports the requested SIMD flag.
+
+#serial 12
+
+AC_DEFUN([AX_CHECK_SIMD],
+[
+ AC_REQUIRE([AC_CANONICAL_HOST])
+
+ case $host_cpu in
+ i[[3456]]86*|x86_64*|amd64*)
+ AX_CHECK_COMPILE_FLAG(-mavx2, ax_cv_support_avx2_ext=yes, [])
+ if test x"$ax_cv_support_avx2_ext" = x"yes"; then
+ SIMD_FLAGS="$SIMD_FLAGS -mavx2"
+ AC_DEFINE(HAVE_AVX2,,
+ [Support AVX2 (Advanced Vector Extensions 2) instructions])
+ AM_CONDITIONAL(HAVE_AVX2, true)
+ else
+ AC_MSG_WARN([Your compiler does not support AVX2 instructions])
+ AM_CONDITIONAL(HAVE_AVX2, false)
+ fi
+
+ AX_CHECK_COMPILE_FLAG(-msse3, ax_cv_support_sse3_ext=yes, [])
+ if test x"$ax_cv_support_sse3_ext" = x"yes"; then
+ SIMD_FLAGS="$SIMD_FLAGS -msse3"
+ AC_DEFINE(HAVE_SSE3,,
+ [Support SSE3 (Streaming SIMD Extensions 3) instructions])
+ AM_CONDITIONAL(HAVE_SSE3, true)
+ else
+ AC_MSG_WARN([Your compiler does not support SSE3 instructions])
+ AM_CONDITIONAL(HAVE_SSE3, false)
+ fi
+
+ AX_CHECK_COMPILE_FLAG(-msse4.1, ax_cv_support_sse41_ext=yes, [])
+ if test x"$ax_cv_support_sse41_ext" = x"yes"; then
+ SIMD_FLAGS="$SIMD_FLAGS -msse4.1"
+ AC_DEFINE(HAVE_SSE4_1,,
+ [Support SSE4.1 (Streaming SIMD Extensions 4.1) instructions])
+ AM_CONDITIONAL(HAVE_SSE4_1, true)
+ else
+ AC_MSG_WARN([Your compiler does not support SSE4.1 instructions])
+ AM_CONDITIONAL(HAVE_SSE4_1, false)
+ fi
+ ;;
+ esac
+
+ AC_SUBST(SIMD_FLAGS)
+])